Torsion beam suspension

Abstract

A torsion beam suspension capable of preventing an abrupt rigidity change in a connection part between a trailing arm and a torsion beam is provided. The present invention is characterized in that in a torsion beam suspension 100 in which to right and left trailing arms 50 extending in a front-rear direction of a vehicle body and swinging vertically, a torsion beam 16 extending in a right and left direction of the vehicle body is joined, two or more types of rigidity adjustment portions 15, 18, 24 and 25 which adjust a rigidity from the trailing arms to the torsion beam are disposed with positions of the rigidity adjustment portions displaced from each other.

The invention claimed is: 
     
       1. A torsion beam suspension having a first member including an opening whose section is formed to have a U-shape; and second members which are arranged in pair in a right and left direction when mounted on a vehicle and which contact the first member at an edge portion of the U-shaped section in the first member, the torsion beam suspension comprising:
 right and left trailing arms which extend in a front-rear direction of the vehicle and are capable of swinging vertically, the trailing arms being formed with a pair of component members arranged at the right and left of the first member when mounted on the vehicle and being formed with the pair of the second members; and 
 a U-shaped torsion beam whose section has an opening and which is arranged between the pair of component members, 
 wherein two or more types of rigidity adjustment portions, which adjust a rigidity from the trailing arms to the torsion beam when the torsion beam is twisted, are disposed with positions of the rigidity adjustment portions displaced from each other, 
 one of the rigidity adjustment portions is configured with a beam connection which connects with the torsion beam in the second member, 
 the beam connection includes two or more extension portions extending from a contact part at which the second member contacts the first member to a bottom of the U-shaped section of the torsion beam, and 
 the extension portions are configured astride the axis of the torsion beam to have different lengths. 
 
     
     
       2. The torsion beam suspension according to  claim 1 , wherein
 the extension portions are arranged such that a part having a shorter distance from an axial center of a tire has a higher rigidity. 
 
     
     
       3. The torsion beam suspension according to  1 , wherein the extension portions are arranged to have different rigidities centered around an axis of the torsion beam. 
     
     
       4. The torsion beam suspension according to  1 , wherein the first member is formed by a method of a tailored blank configured with two or more plate materials each having a different plate thickness, and
 one of the rigidity adjustment portions is configured with a part at which the plate thickness of the two or more plate materials is switched in the first member. 
 
     
     
       5. The torsion beam suspension according to  1 , wherein one of the rigidity adjustment portions is configured by continuously changing a shape of a section crossing an axis direction from the component members to the torsion beam in the first member.